Conventionally, in motion guide devices such as a linear guide, a linear guide device, a ball spline device, and a ball screw device, since members constituting such a device move with repeated rolling and sliding motions, a high hardness metal material such as high-carbon chromium bearing steel, stainless steel, or case-hardening steel has been used for the structural members.
However, due to the requirement for expanding the application range of motion guide devices in recent years, lightweight devices are particularly required, and ideas for reducing weight have been proposed to respond to this requirement. For example, Patent Literature 1 of this applicant discloses a motion guide device using fiber reinforced plastics (FRP) that is a material having strength and rigidity equivalent to those of a metal material such as steel, and also achieves weight reduction. This FRP reinforces plastics by using fiber and resin, can significantly improve strength, and is a material used in various fields such as a space and aviation industry, a motorcycle industry, an automobile industry, a railway industry, and a construction industry, and a medical field. However, conventional FRP has been inferior in abrasion resistance as compared with metal materials. For this reason, the applicant has developed a technique for using FRP to motion guide devices, and proposed a motion guide device achieving weight reduction that was not able to be achieved by the technology using only metal materials in Patent Literature 1.